Protractor.



PATENTED DEC. 6, 1904.

P. E. VANDERGOOK.

PROTRAGTOR.

APPLIOATION FILED APR. 26, 1004.

N0 MODEL.

nve ntor.

Attorney UNITED STATES Patented December 6, 1904.

PATENT OFFICE.

FRANK E. VANDERCOOK, OF WATERBURY, CONNECTICUT, ASSIGNOR OF ONE-HALF TO CHARLES E. SPENCER, OF l VATERBURY, CONNECTICUT.

PROTRACTOR.

SPECIFICATION forming part of Letters Patent No. 776,817, dated December 6, 1904.

Applica ion filed April 26, 1904- all whom zit may concern: I

Be it known that I, FRANK E.VANDERGOOK,

a citizen of the United States, residing at W'aterbury, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Protractors, of which the followingis a specification, reference being had therein to the accompanying drawings.

My invention relates to new and useful improvements in protractors, and refers more especially to that type of protractor which is primarily used in determining the angle upon which work maybe set in a lathe, and has for its object, among other things, the construction of a protractor which can be inserted within the tool-post of a lathe and the desired angle obtained accurately in the shortest possible time, a further object being to so design the device that it will be simple in structure and manufactured at the minimum cost.

To these and other ends my invention consists in the protractor having certain details of construction and combination of parts, as will. be hereinafter described, and more particularly pointed out in the claims.

Referring to the drawings, in which like numerals of reference designate like parts in the several figures, Figure 1 is a view of the live and dead centers of an engine-lathe with a cylindrical block mounted thereon. Fig. 2 is a plan view of my improved protractor. Fig. 3 is a longitudinal sectional elevation thereof upon line 3 3 of Fig. 2, and Fig. 4c is a plan view of amodified form of my improved protractor.

In carrying out my invention I provide a body member 1 of substantially the same dimensions in cross-section as the shank of the ordinary lathe-tool and form the forward end 4 thereof with an overhanging lip 2. within which is fixed a stud or pintle 3. This stud may be made integral with the body member or separate and secured therein by any of the means common to the art. Pivotally mounted on said pintle 3 is a zero-plate 4, having a stud 5 fixed in its rear end which projects upwardly therefrom. Also mounted upon said pintle 3 is the angle-plate 6, having the edges 7 and 8 at right angles to each other and the rear Serial No. 205,038. (No model.)

edge 9 formed in the arc of a circle drawn 5 with the pintle 3 as a center, which edge is graduated, as shown in Fig. 2. Fixed into the forward end of said body member 1 and adjacent to the pintle 3 is the threaded stud 10, which passes upwardly through a curved slot 11- in the zero-plate 4 and the curved slot 12 in the angle-plate 6 and being surrounded by a washer 13, which lies upon the top face of the angle-plate 6, and threaded thereon is the thumb-nut 1 1. Also fixed in the body member 1 to the rear of the zero-plate 4: is the stud 15, upon which is a washer 16, which overlaps the rear edge of the zero-plate 1 and rests upon the top thereof, and a thumb-nut 17, which is threaded onto said stud.

In operation my device is securely fastened within the tool-post of the lathe, preferably with the parts in the relative positions occupied by them in Fig. 2 and the edge 8 of the angleplate substantially parallel with the 7 face-plate. To obtain the desired angle, the edge 8 is first brought up against the face of the face-plate, (not shown, but which is common in all lathes), and the zero-plate 1 is then shifted so that the notch in the post 5 is directly opposite the zero-point. The zeroplate is then held against movement by rotating the thumb nut 17, which presses the washer 16 onto the top of said plate and clamps it in position. The desired angle is then obtained by shifting the angle-plate so that the proper graduation is opposite the notch in the post 5, after which the plate is locked against movement by means of the thumbnut 14;; The piece to be turned can now be 5 placed between the centers of the lathe and the center in the tail-stock shifted so as to bring the same to the proper position whereby it may be turned at the required angle.

This protractor may be used for purposes 9 other than those above set forth.

In Fig. 4 I have shown a modification of my invention in which the zero-plate 4 does not extend beneath the angle-plate 6. Neither is there a zero-post 5 connected therewith; but the plate is fastened to the body member 1 by means of a stud 19 passing through a slot 20 through the plate and having a thumb-nut 21,which bears upon a washer 22, lying upon the top of said zero-plate 4: The operation of my modification is exactly the same as that of the protractor above described, the zeroplate being shifted in substantially the same manner and locked when the zero position is obtained. The zero-plate, however, being entirely free and independent from the angleplate 6 is less likely to become disarranged by the movement thereof.

There are many minor changes and alterations that can be made within my invention aside from those herein suggested, and I would therefore have it understood that I do not limit myself to the exact construction herein shown and described, but claim all that falls fairly Within the spirit and scope of my invention.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a protractor of the character described, the combination with the body member; of an angle-plate, having two straight edges at substantially a right angle to each other and a curved edge connecting said straight edges movably secured to said body member; a zeroplate movably secured to said body member and cooperating with the curved edge of said angle-plate to indicate the degrees of movement of said angle-plate; and independent means for securing each of said plates in any of their adjusted positions.

2. In a protractor of the character described, the combination with the body member 1, having the lip 2 thereon; of the stud 3 fixed in said body member; zero-plate 4 mounted on said stud; means, as the stud 15 and nut 17 for rigidly securing said Zero-plate; angleplate 6 mounted on the said stud 3; and means, as the stud 10 and nut 14, for rigidly securing said angle-plate in any of its adjusted positions.

In testimony whereof Iaflix my signature in presence of two witnesses.

FRANK E. VANDERCOOK.

WVitnesses:

THEo. E. ROGERS, JAs. PEPE. 

